Conventionally, there is a known sample processing apparatus capable of transporting a sample rack that holds multiple sample containers to a sample processing unit such as a blood analyzer, and processing samples contained in the sample containers held by the sample rack by means of the sample processing unit (e.g., blood analysis).
U.S. Pat. No. 5,972,295 discloses a sample testing system that includes: an analysis part for performing sample analysis; a transport line for transporting a sample rack to the analysis part; a rack supply part for supplying the transport line with a sample rack that has been fed by a user; a rack collection part for collecting and storing a sample rack for which analysis has been performed by the analysis part; a standby part for receiving, from the transport line, the sample rack for which the analysis has been performed by the analysis part and provisionally accommodating the sample rack; a control section for determining whether or not the sample rack accommodated in the standby part requires retesting; and a distribution switching part for distributing, among sample racks, a sample rack that requires retesting to the return line and a sample rack that does not require retesting to the rack collection part. In the sample testing system disclosed in U.S. Pat. No. 5,972,295, a sample rack that does not require retesting is collected in the rack collection part without being transported to the return line, and a sample rack that requires retesting is transported by the return line to the entrance of the transport line, and then transported to the analysis part by the transport line again. Thereafter, the sample rack is collected in the rack collection part.
However, in the sample testing system disclosed by U.S. Pat. No. 5,972,295, all the sample racks fed by a user are eventually stored by the rack collection part. Accordingly, the sample racks having been collected in the rack collection part include a sample rack holding samples that have been tested properly, a sample rack holding samples that are to be retested by an apparatus different from the analysis part of the system, a sample rack holding samples that have not been tested due to errors in sample bar code reading, etc. For this reason, a user is required to separate the sample racks collected in the rack collection part in order to send the sample racks to their respective following steps (e.g., discarding, storing, retesting by a different apparatus, and re-affixing of bar code labels). Thus, the burden is greatly imposed on the user.